st: AW: Box-Cox double hurdle

<>
" Please help me find the way out of this problem."
Please help us find your Moffatt (2005)...
HTH
Martin
-----Ursprüngliche Nachricht-----
Von: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Patrick
Hitayezu
Gesendet: Montag, 17. August 2009 22:50
An: statalist@hsphsun2.harvard.edu
Cc: p.moffatt@uea.ac.uk
Betreff: st: Box-Cox double hurdle
Dear All,
I am trying to estimate a Box-Cox Double-Hurdle model using the code
provided by Moffatt (2005). I have set the value of lambda at 0.7 and the
seed at 12678741. I have 17 variables in my model and 514 observations. The
dependent variable in my model exhibits a strong positive skewness (to
justify the use of the Box-Cox DH). Tobit and Double-Hurdle results (before
Box-Cox transformation) are running well with some significant p-values.
However, I am encountering problems after Box-Cox transformation as follows:
1. NONE of the p-values in the Box-Cox tobit is turning out to be
significant and the Prob > chi2 = 1.0000 !?
2. The Box-Cox p-tobit is reporting this error:
initial: log likelihood = -<inf> (could not be evaluated)
could not find feasible values
r(491);
2. ALL the p-values in eq1 of the Box-Cox Double Hurdle are insignificant
and the Prob > chi2 = 1.0000 !?
Please help me find the way out of this problem.
Regards,
Patrick
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/